Cui Haochen, Li Peixun, Zhang Wenjing, Luo Yang, Rao Zhonghao
Hebei Engineering Research Center of Advanced Energy Storage Technology and Equipment, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China.
Hebei Key Laboratory of Thermal Science and Energy Clean Utilization, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China.
ACS Appl Mater Interfaces. 2025 Sep 17;17(37):52622-52630. doi: 10.1021/acsami.5c11426. Epub 2025 Sep 4.
Lithium metal batteries (LMBs) are expected to increase energy density due to the high capacity and low electrode potential of lithium metal. However, lithium dendrite growth and organic liquid electrolytes exacerbate the risk of thermal runaway. To improve the safety of the battery, a multifunctional flame-retardant separator was developed through the synergistic effect of decabromodiphenyl ethane (DBDPE)/AlO nanoparticle composite modification. Among these, DBDPE acts as a flame retardant to reduce the combustibility of the battery, while AlO with high mechanical strength inhibits dendrite growth, and its amphiphilic nature favors the uniform distribution of lithium ions. Thus, a multifunctional flame-retardant separator simultaneously achieves excellent flame suppression, enhanced thermal conductivity (71.3 mW·m k), and excellent electrochemical performance. Lithium (Li) symmetrical batteries based on this separator stably run over 500 h at a current density of 0.5 mA·cm, and Li/LiFePO batteries retain a capacity of 138 mAh g capacity over 100 cycles at a rate of 0.5 C. This flame-retardant separator design, leveraging synergistic regulation of microstructure and thermal properties, provides a groundbreaking roadmap for suppressing thermal runaway while maintaining electrochemical performance, thereby redefining safety paradigms for next-generation high-energy-density battery systems.
